Adjust the layout if a QGraphicsWidget is explicitly hidden

Task-number: QTBUG-20132
Change-Id: Iab59fc9b61d4ca1bb2208c479a027da6eb0283a9
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>
(cherry picked from qtbase/bf200fc948d89e1a735a8bcca879654028f944d2)

6 files changed, 131 insertions, 1 deletions

diff --git a/src/gui/graphicsview/qgraphicswidget.cpp b/src/gui/graphicsview/qgraphicswidget.cpp
index 2883945..2497742 100644
--- a/src/gui/graphicsview/qgraphicswidget.cpp
+++ b/src/gui/graphicsview/qgraphicswidget.cpp
@@ -1138,6 +1138,9 @@ QVariant QGraphicsWidget::itemChange(GraphicsItemChange change, const QVariant &
                 setAttribute(Qt::WA_Resized, false);
             }
         }
+        // layout size hint only changes if an item changes from/to explicitly hidden state
+        if (value.toBool() || d->explicitlyHidden)
+            updateGeometry();
         break;
     case ItemVisibleHasChanged:
         if (!value.toBool()) {
diff --git a/src/gui/graphicsview/qgridlayoutengine.cpp b/src/gui/graphicsview/qgridlayoutengine.cpp
index b2e963b..74a074f 100644
--- a/src/gui/graphicsview/qgridlayoutengine.cpp
+++ b/src/gui/graphicsview/qgridlayoutengine.cpp
@@ -49,6 +49,7 @@
 #include "qgridlayoutengine_p.h"
 #include "qstyleoption.h"
 #include "qvarlengtharray.h"
+#include "qgraphicswidget_p.h"
 
 #include <QtDebug>
 #include <QtCore/qmath.h>
@@ -698,6 +699,14 @@ QRectF QGridLayoutItem::geometryWithin(qreal x, qreal y, qreal width, qreal heig
     }
 }
 
+bool QGridLayoutItem::isIgnored()
+{
+    if (QGraphicsItem *item = layoutItem()->graphicsItem()) {
+        return QGraphicsItemPrivate::get(item)->explicitlyHidden;
+    }
+    return false;
+}
+
 void QGridLayoutItem::setGeometry(const QRectF &rect)
 {
     q_layoutItem->setGeometry(rect);
@@ -1410,7 +1419,7 @@ void QGridLayoutEngine::fillRowData(QGridLayoutRowData *rowData, const QLayoutSt
             if (rowIsIdenticalToPrevious && item != itemAt(row - 1, column, orientation))
                 rowIsIdenticalToPrevious = false;
 
-            if (item)
+            if (item && !item->isIgnored())
                 rowIsEmpty = false;
         }
 
diff --git a/src/gui/graphicsview/qgridlayoutengine_p.h b/src/gui/graphicsview/qgridlayoutengine_p.h
index 1f1078d..88e3501 100644
--- a/src/gui/graphicsview/qgridlayoutengine_p.h
+++ b/src/gui/graphicsview/qgridlayoutengine_p.h
@@ -289,6 +289,7 @@ public:
     QSizeF sizeHint(Qt::SizeHint which, const QSizeF &constraint = QSizeF()) const;
     QGridLayoutBox box(Qt::Orientation orientation, qreal constraint = -1.0) const;
     QRectF geometryWithin(qreal x, qreal y, qreal width, qreal height, qreal rowDescent) const;
+    bool isIgnored();
 
     QGraphicsLayoutItem *layoutItem() const { return q_layoutItem; }
 
diff --git a/tests/auto/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp b/tests/auto/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp
index 68ad99d..3bd9918 100644
--- a/tests/auto/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp
+++ b/tests/auto/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp
@@ -132,6 +132,7 @@ private slots:
     void heightForWidthWithSpanning();
     void stretchAndHeightForWidth();
     void testDefaultAlignment();
+    void hiddenItems();
 };
 
 class RectWidget : public QGraphicsWidget
@@ -3484,6 +3485,70 @@ void tst_QGraphicsGridLayout::testDefaultAlignment()
     QCOMPARE(w->geometry(), QRectF(0,0,50,50));
     QCOMPARE(w2->geometry(), QRectF(0,50,100,100));
 }
+
+static RectWidget *addWidget(QGraphicsGridLayout *grid, int row, int column)
+{
+    RectWidget *w = new RectWidget;
+    w->setPreferredSize(20, 20);
+    grid->addItem(w, row, column);
+    return w;
+}
+
+static void setVisible(bool visible, QGraphicsWidget **widgets)
+{
+    for (int i = 0; i < 3; ++i)
+        if (widgets[i]) widgets[i]->setVisible(visible);
+}
+
+void tst_QGraphicsGridLayout::hiddenItems()
+{
+    QGraphicsWidget *widget = new QGraphicsWidget;
+    QGraphicsGridLayout *layout = new QGraphicsGridLayout(widget);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->setSpacing(2);
+
+    // Create a 3x3 layout
+    addWidget(layout, 0, 0);
+    RectWidget *w01 = addWidget(layout, 0, 1);
+    addWidget(layout, 0, 2);
+    RectWidget *w10 = addWidget(layout, 1, 0);
+    RectWidget *w11 = addWidget(layout, 1, 1);
+    RectWidget *w12 = addWidget(layout, 1, 2);
+    addWidget(layout, 2, 0);
+    RectWidget *w21 = addWidget(layout, 2, 1);
+    addWidget(layout, 2, 2);
+
+    QGraphicsWidget *middleColumn[] = {w01, w11, w21 };
+    QGraphicsWidget *topTwoOfMiddleColumn[] = {w01, w11, 0 };
+
+    // hide and show middle column
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    setVisible(false, middleColumn);   // hide middle column
+    QCOMPARE(layout->preferredWidth(), qreal(42));
+    setVisible(true, middleColumn);    // show middle column
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+
+    // Hide only two items, => column should not collapse
+    setVisible(false, topTwoOfMiddleColumn);
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+
+
+    QGraphicsWidget *middleRow[] = {w10, w11, w12 };
+    QGraphicsWidget *leftMostTwoOfMiddleRow[] = {w10, w11, 0 };
+
+    // hide and show middle row
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+    setVisible(false, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(42));
+    setVisible(true, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+    // Hide only two items => row should not collapse
+    setVisible(false, leftMostTwoOfMiddleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+
+}
+
+
 QTEST_MAIN(tst_QGraphicsGridLayout)
 #include "tst_qgraphicsgridlayout.moc"
 
diff --git a/tests/auto/qgraphicslayout/tst_qgraphicslayout.cpp b/tests/auto/qgraphicslayout/tst_qgraphicslayout.cpp
index 1e20bb7..52ce9bb 100644
--- a/tests/auto/qgraphicslayout/tst_qgraphicslayout.cpp
+++ b/tests/auto/qgraphicslayout/tst_qgraphicslayout.cpp
@@ -62,6 +62,7 @@ private slots:
     void compressLayoutRequest();
     void automaticReparenting();
     void verifyActivate();
+    void sizeHintOfHiddenLayout();
     void invalidate();
     void moveAndResize_data();
     void moveAndResize();
@@ -299,6 +300,29 @@ void tst_QGraphicsLayout::verifyActivate()
 
 }
 
+
+void tst_QGraphicsLayout::sizeHintOfHiddenLayout()
+{
+    QGraphicsScene scene;
+    QGraphicsWidget *window = new QGraphicsWidget(0, Qt::Window);
+    scene.addItem(window);
+    TestLayout *lout = new TestLayout(window);
+    lout->setContentsMargins(1,2,2,1);
+    QGraphicsWidget *w = new QGraphicsWidget;
+    w->setPreferredSize(20, 20);
+    w->setMaximumSize(50, 50);
+    lout->addItem(w);
+    window->setLayout(lout);
+
+    for (int pass = 0; pass < 3; ++pass) {
+        QCOMPARE(lout->sizeHint(Qt::MinimumSize), QSizeF(3,3));
+        QCOMPARE(lout->sizeHint(Qt::PreferredSize), QSizeF(23,23));
+        QCOMPARE(lout->sizeHint(Qt::MaximumSize), QSizeF(53,53));
+        window->setVisible(pass % 2);
+    }
+}
+
+
 static void clearAllCounters(TestGraphicsWidget *widget)
 {
     if (!widget)
diff --git a/tests/auto/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp b/tests/auto/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp
index dd5b9d0..ab20bfc 100644
--- a/tests/auto/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp
+++ b/tests/auto/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp
@@ -108,6 +108,7 @@ private slots:
     void testOffByOneInLargerLayout();
     void testDefaultAlignment();
     void combineSizePolicies();
+    void hiddenItems();
 
     // Task specific tests
     void task218400_insertStretchCrash();
@@ -1649,6 +1650,33 @@ void tst_QGraphicsLinearLayout::combineSizePolicies()
     QCOMPARE(layout->maximumHeight(), qreal(200));
 }
 
+void tst_QGraphicsLinearLayout::hiddenItems()
+{
+    QGraphicsWidget *widget = new QGraphicsWidget;
+    QGraphicsLinearLayout *layout = new QGraphicsLinearLayout(Qt::Horizontal, widget);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->setSpacing(2);
+
+    RectWidget *w1 = new RectWidget;
+    w1->setPreferredSize(QSizeF(20, 20));
+    layout->addItem(w1);
+
+    RectWidget *w2 = new RectWidget;
+    w2->setPreferredSize(QSizeF(20, 20));
+    layout->addItem(w2);
+
+    RectWidget *w3 = new RectWidget;
+    w3->setPreferredSize(QSizeF(20, 20));
+    layout->addItem(w3);
+
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    w2->hide();
+    QCOMPARE(layout->preferredWidth(), qreal(42));
+    w2->show();
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+}
+
+
 QTEST_MAIN(tst_QGraphicsLinearLayout)
 #include "tst_qgraphicslinearlayout.moc"